Doing anything else is just far too expensive.

Plutonium can be used to make nuclear bombs. But it can also be recycled and used as a fuel in nuclear reactors. According to the authors of a Nature editorial, the UK—which has the largest civilian stockpile of plutonium, around 90 tons—should skip recycling and stockpiling plutonium and simply bury it. They argue that recycling is simply too expensive and risky.

World stockpiles hold about 500 tons of plutonium, which is an enough to make 100,000 nuclear weapons. That number goes up quite a bit when you account for the amount locked in nuclear waste—around 620 tons in the United States alone, a figure that increases by 23 tons every year.

Now, at first glance, the idea of just burying hundreds of tons of useful plutonium seems ridiculous. With all the world’s energy concerns, why wouldn’t we use it? As we covered in our recent feature on the future of nuclear energy in the US, plutonium can supplement traditional uranium fuel to power existing nuclear reactors. This combined fuel, made up of plutonium and depleted uranium, is called mixed oxide (MOX). Plutonium is even more effective in fast breeder reactors, but these haven’t been commercially successful, despite development work dating back to the 1950s.

Radioactive recycling

France has been separating and recycling plutonium for use in MOX fuel for almost 20 years (although the program was originally for nuclear weapons). However, since reprocessing is so expensive, using recycled plutonium actually adds nearly $750 million a year to electricity generation costs compared to burying it and burning uranium alone.

Both Japan and Great Britain pursued similar plutonium recycling schemes, but neither were functional, much less successful. Japan’s plutonium reprocessing plant only operated for two years, separating just four tons before malfunctioning and shutting down in 2008. The same malfunction killed an attempted restart in January and, since the Fukushima disaster, the future of Japan’s entire nuclear program is up in the air. As of Saturday, none of the country’s nuclear reactors are running.

Britain built a MOX fabrication plant in 2001 that operated at one percent capacity until it was closed last year. That experiment cost $2.3 billion.

Why is plutonium reprocessing and MOX fuel fabrication so expensive? For one thing, the plutonium has to be separated from radioactive nuclear waste. Most approaches are variations on the Plutonium-URanium Extraction (PUREX) technique, which was developed during the Manhattan Project. This process involves dissolving spent fuel in nitric acid, then extracting plutonium and uranium using an organic solvent. This may sound simple enough, but handling and reprocessing extremely radioactive used fuel is expensive.

Creating MOX fuel pellets, on the other hand, requires precise machining of fuel pellets to fit in long zirconium tubes. Add these costs to the already expensive reprocessing stage, and you have plutonium-based fuel that costs around five times that of new uranium fuel.

Just bury it already!

We’ve established that recycling plutonium is more expensive than it’s worth. What else can we do with it? According to the authors of the commentary, the safest and most cost-effective route is to simply stop reprocessing and dispose of our existing stockpiles of plutonium. First, the plutonium would be “immobilized” by encasing it in ceramic. Then, in order to prevent would-be nuclear terrorists from stealing it to make a nuclear bomb, this immobilized plutonium could be buried with radioactive spent fuel or nuclear waste in 500-meter deep repositories.

Another option would be to dump this mixture into 5000-meter-deep boreholes where it could never be retrieved, although this seems like the beginning of a story involving mole people.

Although a number of countries are moving forward with plans for storing nuclear waste, the prospect of storing purified plutonium hasn’t been explored extensively since most countries have been pursuing the recycling option.

66 Reader Comments

Breeder reactors, at least until DEMO comes online and makes a mockery of our energy concerns with commercial fusion, seem like by far the best long-term solution to power generation, and just dumping a potentially useful fuel seems very short-sighted.

I'd rather we put significant amounts of effort into developing FBR technology to the point where it's viable, and continue to hold and stockpile the plutonium until that point.

PUREX is a wonderfully efficient process for extracting plutonium. The main concerns most have with it usually aren't associated with cost but with proliferation.

As far as just burying everything, the more we can burn nuclear fuel in reactors, the less long-lived waste we have to bury. While we see burial as a cheaper solution, what about the day in which we discover how to more cheaply process and/or discover a new use for some of the decay products, but can't get to them because we either dropped them in whole or buried them inside a mountain which has now glassed over or been filled in?

As far as commercial success goes, all that takes is the right kind of initiative. If you want to avoid burying this stuff, put tax credits it or (gasp) the Carbon credit system. Nuclear, with its complete lack of CO2 emissions, looks amazing at that point. (Plus, it helps if the government doesn't just keep shutting down breeder reactors over and over)

Breeder reactors, at least until DEMO comes online and makes a mockery of our energy concerns with commercial fusion, seem like by far the best long-term solution to power generation, and just dumping a potentially useful fuel seems very short-sighted.

I'd rather we put significant amounts of effort into developing FBR technology to the point where it's viable, and continue to hold and stockpile the plutonium until that point.

1 keeping primary and secondary coolants apart, one hairline crack results in a water/sodium explosion and

2 keeping the sodium molten at all times to avoid the cooling system seizing up.

Basically there don't seem to be practical ways of maintaining such a system for a reasonable plant lifetime. Much research money has already been spent on this over many decades. More should not be spent on it unless promising engineering approaches not yet tried seem likely to be able to get past these basic engineering problems.

Where you state fusion, you probably mean fission. Managed terrestrially based fusion is also a research proposition, but this doesn't seem much closer to commercial than when 40 years ago it was promised as at least 30 years away from commercial use. We don't seem any closer to that now. Also the aftermath of Fukushima since when Japan's entire nuclear capability has been shut down demonstrates that politics can turn against fission if anything goes badly wrong.

Kyle, we aren't burying the plutonium because the last project we tried for that cost 90 billion dollars and still isn't usable (Yucca mountain.)

With that in perspective, reprocessing sure as hell seems cheaper based on the numbers provided in the article. Can you do an update using current data that covers the cost of burying vs cost of reprocessing in better detail?

Breeder reactors, at least until DEMO comes online and makes a mockery of our energy concerns with commercial fusion, seem like by far the best long-term solution to power generation, and just dumping a potentially useful fuel seems very short-sighted.

I'd rather we put significant amounts of effort into developing FBR technology to the point where it's viable, and continue to hold and stockpile the plutonium until that point.

1 keeping primary and secondary coolants apart, one hairline crack results in a water/sodium explosion and

2 keeping the sodium molten at all times to avoid the cooling system seizing up.

Basically there don't seem to be practical ways of maintaining such a system for a reasonable plant lifetime.

And while sodium explosions are a concern, they wouldn't result in large scale nuclear accidents, as far as I can tell. It would be an on-site hazard for personnel, but not the population. Lead cooled is also an option though.

I have to really disagree with permanently burying plutonium stockpiles. At our current rate of consumption, uranium reserves (known and unknown) will only last around 200 years. I know it's unlikely, but what if we can't find a better energy solution in that time? Until some other energy source is within our grasp, it would be a mistake (IMO) to not continue work in the area of MOX fuel fabrication, and keep these stockpiles in a retrievable location.

Kyle, we aren't burying the plutonium because the last project we tried for that cost 90 billion dollars and still isn't usable (Yucca mountain.)

With that in perspective, reprocessing sure as hell seems cheaper based on the numbers provided in the article. Can you do an update using current data that covers the cost of burying vs cost of reprocessing in better detail?

I'm under the impression that getting new uranium is more difficult every day. I don't know if that is because the cost of oil going up or availability or both.

Keeping the above in mind if uranium is harder and harder to get will it always be more expensive to recycle the plutonium? Even though it's not cheaper now would it be better to hold on to it for when it will be cheaper than processing uranium? (i understand that processing costs could go up equally for both and it may never be cheaper)

I have to really disagree with permanently burying plutonium stockpiles. At our current rate of consumption, uranium reserves (known and unknown) will only last around 200 years. I know it's unlikely, but what if we can't find a better energy solution in that time? Until some other energy source is within our grasp, it would be a mistake (IMO) to not continue work in the area of MOX fuel fabrication, and keep these stockpiles in a retrievable location.

Kyle, we aren't burying the plutonium because the last project we tried for that cost 90 billion dollars and still isn't usable (Yucca mountain.)

With that in perspective, reprocessing sure as hell seems cheaper based on the numbers provided in the article. Can you do an update using current data that covers the cost of burying vs cost of reprocessing in better detail?

Salt disposal of DOE's legacy transuranic waste has worked well so there is research going into salt based disposal of high level nuclear waste. Not that I think permanent disposal of usable material would be the wisest decision for the nuclear energy, there are still prospects of safe, successful storage.

Give a few pounds to ESA, they need it for the ion drive on the JUICE spacecraft. If NASA had a decent budget ( say 20% of the US military budget as they should have) they would be joined in to that project and there would not be a problem.

I have to really disagree with permanently burying plutonium stockpiles. At our current rate of consumption, uranium reserves (known and unknown) will only last around 200 years. I know it's unlikely, but what if we can't find a better energy solution in that time? Until some other energy source is within our grasp, it would be a mistake (IMO) to not continue work in the area of MOX fuel fabrication, and keep these stockpiles in a retrievable location.

Agreed, though these reserves, just like Yucca, would become future uranium mines anyway.

Our U-235 reserves would sure last a hell of a lot longer in breeding, and then we wouldn't be generating this plutonium in the first place.

whatever happened to the idea of placing the plutonium in some sort of large metal slug and then dropping it into the ocean near a subduction zone? The idea is that by the time the slug hits the ocean floor, depending on it profile and mass, it could embed itself pretty deep, and in 1000 years or so will be on its way back into the Earth's mantle.

".. using recycled plutonium actually adds nearly $750 million a year to electricity generation costs compared to burying it and burning uranium alone.

Here's same article at SciAmerican

"...By one French estimate from 2000 recycling plutonium in this way adds $750 million to the annual cost of "

Google "how-to-rid-the-world-of-the-element-from-hell"

Note how Kyle accidently on purpose forget to mention the "one estimate" and the way back year 2000.

In fact, Areva which does all the reprocessing tells us that it now costs about the same to Purex reprocess as it does to make up new fuel from uranium.

What Kyle again accidently on purpose forgets to mention is that the extracted plutonium from nuclear fuel is worthless for nuclear weapons use as the mix of plutonium isotopes would make such a weapon impossible to build.

Finally like all stories done by Big Oil['s captive media the fact that GE has offered to build at Sellafield at its cost and at its own risk two IFR reactors designed commercial ready to build at Idaho National Labs under its Prizm brand. The IFR uses pyroprocessing to burn old nuke fuel with enough lying around to power the world for a thousand years. India has a 500 MW version first of 5 to 2020 coming on line this year at $1.5B/Gw less than half the cost of today's PWR. The IFR project in 1996 was shut down by Bill Clinton in exchange for BiG Oil campaign donations.

All the world's nuke fuel waste would fit on a football field. By the time the IFR was finished with it, it would all fit in an equipment locker whoae rad levels would be similar to natural uranium in less than 300 years.

whatever happened to the idea of placing the plutonium in some sort of large metal slug and then dropping it into the ocean near a subduction zone? The idea is that by the time the slug hits the ocean floor, depending on it profile and mass, it could embed itself pretty deep, and in 1000 years or so will be on its way back into the Earth's mantle.

Was thinking that myself...

And, on the topic--is there a reliable full-cost analysis of nuclear power compared to other conventional methods such as coal/hydro/solar?

I thought that it was so cheap to mine uranium that it became unprofitable. I know there's large deposits in the US and Australia. Keep rolling with U but stash our plutonium reserves somewhere in case we need them later.

".. using recycled plutonium actually adds nearly $750 million a year to electricity generation costs compared to burying it and burning uranium alone.

Here's same article at SciAmerican

"...By one French estimate from 2000 recycling plutonium in this way adds $750 million to the annual cost of "

Google "how-to-rid-the-world-of-the-element-from-hell"

Note how Kyle accidently on purpose forget to mention the "one estimate" and the way back year 2000.

In fact, Areva which does all the reprocessing tells us that it now costs about the same to Purex reprocess as it does to make up new fuel from uranium.

What Kyle again accidently on purpose forgets to mention is that the extracted plutonium from nuclear fuel is worthless for nuclear weapons use as the mix of plutonium isotopes would make such a weapon impossible to build.

Finally like all stories done by Big Oil['s captive media the fact that GE has offered to build at Sellafield at its cost and at its own risk two IFR reactors designed commercial ready to build at Idaho National Labs under its Prizm brand. The IFR uses pyroprocessing to burn old nuke fuel with enough lying around to power the world for a thousand years. India has a 500 MW version first of 5 to 2020 coming on line this year at $1.5B/Gw less than half the cost of today's PWR. The IFR project in 1996 was shut down by Bill Clinton in exchange for BiG Oil campaign donations.

All the world's nuke fuel waste would fit on a football field. By the time the IFR was finished with it, it would all fit in an equipment locker whoae rad levels would be similar to natural uranium in less than 300 years.

I don't agree that Ars (Kyle and John) are pro-oil, but I do agree they have an anti-nuclear energy bent to their articles. As good as Ars is at editing most articles, they certainly let a lot of anti-nuclear energy editorial into their articles on nuclear energy. The new Ars 7.0 has promised to allow notable reader comments tacked onto the bottom of the story and I nominate sethdayal's comment.

To give Kyle a bit of a break, he's just summarizing an article by a different author.

Unfortunately, it seems like the primary article doesn't consider alternative options. It only compares PUREX/MOX vs Burying. That's a false dichotomy. There are other potential options on the horizon. Some might work out, some might not, but the point is, don't put it in some permanent burial state where it's almost impossible to retrieve - burning it is probably, ultimately, the better option.

In addition to the IFR-style sodium cooled fast breeders several other posters mentioned, there's also the possibility of using the plutonium to startup Thorium breeder reactors.

To give Kyle a bit of a break, he's just summarizing an article by a different author.

Unfortunately, it seems like the primary article doesn't consider alternative options. It only compares PUREX/MOX vs Burying. That's a false dichotomy. There are other potential options on the horizon. Some might work out, some might not, but the point is, don't put it in some permanent burial state where it's almost impossible to retrieve - burning it is probably, ultimately, the better option.

You know, if I wanted to read articles from other sites, I'd go to other sites. I expect Ars writers to take an article, look at the issue, and expand on it when it needs to be expanded on. Not covering the cost of storage historically while covering the cost of recycling historically is not my idea of good journalism.

I thus make the following declaration:

This is a bad article. What really sucks is that with just a bit more work it could have been a really good article.

I don't think any discussion benefits from accusations of corruption unless there's some actual evidence to back up those claims. Just because you disagree with him (as do I) does not mean he's bought by "Big Oil".

".. using recycled plutonium actually adds nearly $750 million a year to electricity generation costs compared to burying it and burning uranium alone.

Here's same article at SciAmerican

"...By one French estimate from 2000 recycling plutonium in this way adds $750 million to the annual cost of "

Google "how-to-rid-the-world-of-the-element-from-hell"

Note how Kyle accidently on purpose forget to mention the "one estimate" and the way back year 2000.

In fact, Areva which does all the reprocessing tells us that it now costs about the same to Purex reprocess as it does to make up new fuel from uranium.

What Kyle again accidently on purpose forgets to mention is that the extracted plutonium from nuclear fuel is worthless for nuclear weapons use as the mix of plutonium isotopes would make such a weapon impossible to build.

Finally like all stories done by Big Oil['s captive media the fact that GE has offered to build at Sellafield at its cost and at its own risk two IFR reactors designed commercial ready to build at Idaho National Labs under its Prizm brand. The IFR uses pyroprocessing to burn old nuke fuel with enough lying around to power the world for a thousand years. India has a 500 MW version first of 5 to 2020 coming on line this year at $1.5B/Gw less than half the cost of today's PWR. The IFR project in 1996 was shut down by Bill Clinton in exchange for BiG Oil campaign donations.

All the world's nuke fuel waste would fit on a football field. By the time the IFR was finished with it, it would all fit in an equipment locker whoae rad levels would be similar to natural uranium in less than 300 years.

I don't agree that Ars (Kyle and John) are pro-oil, but I do agree they have an anti-nuclear energy bent to their articles. As good as Ars is at editing most articles, they certainly let a lot of anti-nuclear energy editorial into their articles on nuclear energy. The new Ars 7.0 has promised to allow notable reader comments tacked onto the bottom of the story and I nominate sethdayal's comment.

I couldn't agree more with both posters' sentiments. Is there a 'like" button or a nomination method that has been formalized?

BTW, the return to commenter rankings based on length of service is nice but quantity does not equal quality. Having to reach a certain number of posts to achieve a ranking could lead to a lot of "me too" posts. Heck, this one smacks of "me too". Hmm...

Completely unfounded accusations that our author is being paid off by big oil, and a failure to recognize that the author is simply covering someone else's article is not the sort of "quality content" we're going to promote. In fact, unfounded attacks on our writers is a very quick way to get moderated.

Please try to engage in these discussions with something a bit more critical analysis than "i like it, therefore it must be good."

...At our current rate of consumption, uranium reserves (known and unknown) will only last around 200 years. I know it's unlikely, but what if we can't find a better energy solution in that time? Until some other energy source is within our grasp...

That's the kind of figures I've heard too, and a big part of why research on breeder reactors has to be of the utmost importance to big energy consumer, nuclear states (I've hear at a conference that if breeder tech was used current reserves would be sufficient for 20000 years).

But it feels like it's only part of the real issue here...A lot of scientists feel that if we keep going at this rate, environmental pollution will reach the tipping point in about 20 years, but around the globe energy consumption only keeps rising, and when emerging states can't afford clean solutions they switch to good old dirty (and cheap) coal, just like in the USA.

People have to understand that if they want to keep living like they do now while safeguarding the environment, when the rest of the world gets there, they'll have to pay the real energy bill by switching off coal, gas and oil for the more expensive wind, solar and nuclear.

And by the way I always wonder what formulas people in government use to factor the cost of solar plants and wind turbines. In my mind both present, in large scales, huge cost in fabrication (loads of high tech materials), in maintenance (solar panels lose a lot of efficiency if they aren't cleaned once in a while), and still present the issue of having to have a couple of dirty power stations around to manage energy consumption pikes.

Although a number of countries are moving forward with plans for storing nuclear waste, the prospect of storing purified plutonium hasn’t been explored extensively since most countries have been pursuing the recycling option.

I thought the gist of the article was that it was very costly to purify it. If it's already purified, using it should be the cheaper alternative (what am I missing?).

...At our current rate of consumption, uranium reserves (known and unknown) will only last around 200 years. I know it's unlikely, but what if we can't find a better energy solution in that time? Until some other energy source is within our grasp...

That's the kind of figures I've heard too, and a big part of why research on breeder reactors has to be of the utmost importance to big energy consumer, nuclear states (I've hear at a conference that if breeder tech was used current reserves would be sufficient for 20000 years).

The 200 year figure has some problems. . . first, there's still plenty of opportunity to find uranium through exploration (I like how in the quote above, the person says "uranium reserves (known and unknown) will only last around 200 years. . .". If they're UNKNOWN, how can you possibly predict how long they'll last?

But, even assuming that number is correct. . . There is a huge amount of uranium dissolved in the oceans. Japan was doing research on using some sort of fabric material which uranium would stick to, and come out of the water. If that sort of approach can become cheap enough, you can get a virtually endless supply of uranium out of the ocean - for one thing, uranium is constantly, slowly, dissolving out of rocks and soils into ground water, and eventually migrating to the ocean, so even as you pull U out of the ocean, more is leeching into it, so it's essentially renewable.

There's also Thorium, which is 4 to 5 times more abundant than Uranium.

The best use of Plutonium, long term, is probably as a fissile startup charge (a "nuclear seed", if you will), for a LFTR/Thorium Breeder reactor.

The premise of this article is employing tunnel vision, an oversimplification, to support its argument. It overlooks the dynamic relationship between the cost and use of recycled plutonium and the cost of "new" uranium fuel. Uranium is a rather finite resource; the more we use and the faster we use it, the greater the cost of using it. Anything else that results in a reduced rate of use is actually contributing to a lower cost. Thus the use of recycled plutonium actually subsidizes a lower cost for uranium fuel, and this subsidy increases as the reserves of uranium decrease.

Nobody ever said any form of recycling is "cheaper". It's not supposed to be, and isn't. Recycling simply makes more obvious the true costs involved in (sustainable) human resource usage.

We could outsource this problem to SpaceX and let them shoot it at the sun. After all, why pollute the Earth when we have a whole solar system?

I saw a really good explanation of this a while back...I'll do my best to recreate it.

Such waste is typically very heavy and launching things into space is very expensive (thousands per pound). Combine this with the sheer quantity of waste that there is and things start getting really pricey. (the world generates about 10,000 metric tons of high level waste each year)

SpaceX claim to be able to get things into low earth orbit for around $2,500 a pound. That would put the cost at over $55 billion/year assuming SpaceX had the rockets to do this.

This wouldn't solve the problem though. All this does is put a bunch of garbage in orbit. Now getting to the sun is far more difficult; SpaceX doesn't have any rockets that can leave earth's orbit that I am aware of. The only ones I know of with craft that can do this are the likes of NASA and the ESA...at of course much higher rates.

I can't find any good numbers for a trip out of orbit/to the sun, but I would be surprised if anyone could do it for any less than trillions a year.

...You also have the problem that you are putting a bunch of radioactive material on top of a few tons of explosives, and with this many launches it would be very unlikely for there to not be at least a few mishaps.

The article is short-sighted. Current cost does not necessarily equal cost later. It may well be that those stores of plutonium become a very valuable commodity. As some other posters have noted the re-processing has the benefit of separating out re-usable fuel from non-usable fuel, which leaves waste with a far shorter dangerous half-life.

It would have been nice to see comparisons with the amount of radioactivity spewed by coal and/or other costs of energy generation. Some critical thought of "bury it in a hole" as the only alternative seems like a lack of imagination.

Give a few pounds to ESA, they need it for the ion drive on the JUICE spacecraft. If NASA had a decent budget ( say 20% of the US military budget as they should have) they would be joined in to that project and there would not be a problem.

I read about this on CNN just yesterday as well which is why this part makes me scratch my head:

Quote:

the UK—which has the largest civilian stockpile of plutonium, around 90 tons

Is the 90 tons earmarked towards other projects? Or did the ESA never consider RTGs to power JUICE in the first place and CNN's article was a reporter not having a clue?

We could convert it all in to nuclear weapons, launch nukes in every direction from earth, and see if we find an advanced, nuke-proof civilization.

We could call it the Nuclear Search for Extra Terrestrial Intelligence, NSETI!

We have all of this plutonium for what reason? It's a stupid problem that arose from stupid circumstances.

So the idea is on dumping a ton of radioactive material in to holes to pollute who-knows-what and destroy who-knows-what as if we know all the secrets of the earth.

And suddenly we have an earthquake and a volcano showering down plutonium capsules from the sky. Awesome.

Great idea someone wont be angry getting a non functioning nuke dropped in their knee.., although I believe someone clever could make the nuclear waste drive the rocket just for fun, we can call the drive NWD

And I agree just dumping something thats probably is going to come back and haunt us (or if we're lucky another generation) sounds like a master plan....

I think we should try to find a way to make the waste non radioactive, I know there's probably no way to this at the moment (duh..) but investing a lot of research in to it sounds like a basic plan. For example if you have a reactor you need to invest as much in research and "%" amount of your profit in it to... Not really gonna happen but you can always dream....

Kyle Niemeyer / Kyle is a science writer for Ars Technica. He is a postdoctoral scholar at Oregon State University and has a Ph.D. in mechanical engineering from Case Western Reserve University. Kyle's research focuses on combustion modeling.